2008 INFINITI QX56 check engine

DLN-126
< ON-VEHICLE MAINTENANCE >[ATX14B]
TRANSFER OIL FILTER
3. Apply ATF to the two new O-rings (1), and install them on the oil
filter (2).
CAUTION:
Do not reuse O-rings.
4. Install the oil filter to the transfer assembly. Tighten the bolts to the specified torque. Refer to DLN-125, "
Removal and Installa-
tion".
CAUTION:
• Do not damage oil filter.
• Attach oil filter an d tighten bolts evenly.
5. Check the transfer fluid. Refer to DLN-127, "
Inspection".
6. Start the engine for one minute. Then stop the engine and recheck the transfer fluid. Refer to DLN-127, "
Inspection".
WDIA0285E
SDIA2136E
Revision: March 2010 2008 QX56

TRANSFER FLUIDDLN-127
< ON-VEHICLE MAINTENANCE > [ATX14B]
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TRANSFER FLUID
ReplacementINFOID:0000000001604410
CAUTION:
If using the vehicle for towing, the transfer fluid must be replaced as specified. Refer to DLN-127,
"Replacement".
DRAINING
1. Stop engine.
2. Remove the drain plug and gasket and drain the fluid.
3. Install the drain plug with a new gasket to the transfer. Tighten to
the specified torque. Refer to DLN-140, "
Disassembly and
Assembly".
CAUTION:
Do not reuse gasket.
FILLING
1. Remove the filler plug and gasket.
2. Fill the transfer with new fluid until the fluid level reaches the specified limit near the filler plug hole.
CAUTION:
Carefully fill fluid. (Fil l up for approx. 3 minutes.)
3. Leave the vehicle for 3 minutes, and check fluid level again.
4. Install the filler plug with a new gasket to the transfer. Tighten to the specified torque. Refer to DLN-140, "
Disassembly and
Assembly".
CAUTION:
Do not reuse gasket.
InspectionINFOID:0000000001604411
CAUTION:
If using the vehicle for towing, the transfer fluid must be replaced as specified. Refer to MA-12, "
Fluids
and Lubricants".
FLUID LEAKAGE AND FLUID LEVEL
1. Make sure that fluid is not leaking from the transfer assembly or around it.
2. Check fluid level from the filler plug hole as shown.
CAUTION:
Do not start engine while checking fluid level.
3. Install the filler plug with a new gasket to the transfer. Tighten to the specified torque. Refer to DLN-140, "
Disassembly and
Assembly".
CAUTION:
Do not reuse gasket.
SDIA3208E
Fluid grade and capacity : Refer to MA-12, "Fluids and
Lubricants".
SDIA3209E
SDIA3209E
Revision: March 2010 2008 QX56

DLN-138
< ON-VEHICLE REPAIR >[ATX14B]
TRANSFER MOTOR
TRANSFER MOTOR
Removal and InstallationINFOID:0000000001604418
REMOVAL
1. Disconnect the transfer motor connector.
2. Remove the transfer motor air breather hose from the transfer
motor. Refer to DLN-135, "
Removal and Installation".
3. Remove the transfer motor bolts.
4. Remove the transfer motor.
INSTALLATION
1. Apply ATF to the new O-ring and install it to the transfer motor. CAUTION:
Do not reuse O-rings.
2. Fit the double-flat end of the transfer motor shaft into the slot of the sub-oil pump assembly. Then tighten to the specified torque.
Refer to DLN-140, "
Disassembly and Assembly".
CAUTION:
Be sure to install connector bracket.
3. Install the transfer motor air breather hose to the transfer motor. Refer to DLN-135, "
Removal and Installation".
4. Connect the transfer motor connector.
5. Check the transfer fluid. Refer to DLN-127, "
Inspection".
6. Start the engine for one minute. Then stop the engine and recheck the transfer fluid. Refer to DLN-127,
"Inspection".
SDIA2133E
SDIA2787E
Revision: March 2010 2008 QX56

TRANSFER ASSEMBLYDLN-139
< REMOVAL AND INSTALLATION > [ATX14B]
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REMOVAL AND INSTALLATION
TRANSFER ASSEMBLY
Removal and InstallationINFOID:0000000001604419
REMOVAL
1. Set transfer state as 2WD when 4WD shift switch is at 2WD.
2. Remove the undercovers using power tool.
3. Drain the transfer fluid. Refer to DLN-127, "
Replacement".
4. Remove the center exhaust tube and main muffler. Refer to EX-6, "
Removal and Installation".
5. Remove the front and rear propeller shafts. Refer to DLN-184, "
Removal and Installation" (front), DLN-
184, "Removal and Installation" (rear).
CAUTION:
Do not damage spline, sleeve yoke and rear oi l seal when removing rear propeller shaft.
NOTE:
Insert a plug into the rear oil seal after removing the rear propeller shaft.
6. Remove the A/T nuts from the A/T crossmember. Refer to TM-216, "
Removal and Installation (4WD)".
7. Position two suitable jacks under the A/T and transfer assembly.
8. Remove the crossmember. Refer to TM-216, "
Removal and Installation (4WD)".
WARNING:
Support A/T and transfer assembly using two suitable jacks while removing crossmember.
9. Disconnect the electrical connectors from the following: • ATP switch
• Neutral 4LO switch
• Wait detection switch
• Transfer motor
• Transfer control device
• Transfer terminal cord assembly
10. Disconnect each air breather hose from the following. Refer to DLN-135, "
Removal and Installation".
• Actuator
• Breather tube (transfer)
• Transfer motor
11. Remove the transfer control dev ice from the extension housing.
12. Remove the transfer to A/T and A/T to transfer bolts.
13. Remove the transfer assembly. WARNING:
Support transfer assembly with su itable jack while removing it.
CAUTION:
Do not damage rear oil seal (A/T).
INSTALLATION
Installation is in the reverse order of removal.
• Tighten the bolts to specification.
• Fill the transfer with new fluid and check for fluid leakage and fluid level. Refer to DLN-127, "
Replacement".
• Start the engine for one minute. Then stop the engine and recheck the transfer fluid. Refer to DLN-127, "
Inspection".
Transfer bolt torque : 36 N·m (3.7 kg-m, 27 ft-lb)
SMT872C
Revision: March 2010
2008 QX56

DIFFERENTIAL GEAR OILDLN-207
< ON-VEHICLE MAINTENANCE > [FRONT FINAL DRIVE: M205]
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ON-VEHICLE MAINTENANCE
DIFFERENTIAL GEAR OIL
Changing Differential Gear OilINFOID:0000000001604443
DRAINING
1. Stop the engine.
2. Remove the drain plug from the front final drive assembly to drain the differential gear oil.
3. Install the drain plug with sealant applied on the thr eads to the front final drive assembly. Tighten to the
specified torque. Refer to DLN-214, "
Disassembly and Assembly".
• Use High Performance Thread Sealant or equivalent. Refer to GI-15, "
Recommended Chemical Prod-
ucts and Sealants".
FILLING
1. Remove the filler plug from the front final drive assembly.
2. Fill the front final drive assembly with new differential gear oil
until the level reaches the specified level near the filler plug hole.
3. Install the filler plug with sealant applied on the threads to the front final drive assembly. Tighten to the specified torque. Refer
to DLN-214, "
Disassembly and Assembly".
• Use High Performance Thread Sealant or equivalent. Refer to GI-15, "
Recommended Chemical Products and Sealants".
Checking Differential Gear OilINFOID:0000000001604444
DIFFERENTIAL GEAR OIL LEAKAGE AND LEVEL
1. Make sure that differential gear oil is not leaking from the front final drive assembly or around it.
2. Check the differential gear oil level from the filler plug hole as
shown.
CAUTION:
Do not start engine while checki ng differential gear oil level.
3. Install the filler plug with sealant applied on the threads to the front final drive assembly. Tighten to the specified torque. Refer
to DLN-214, "
Disassembly and Assembly".
• Use High Performance Thread Sealant or equivalent. Refer to GI-15, "
Recommended Chemical Products and Sealants".
Differential gear oil
grade and capacity
: Refer to
MA-12, "
Fluids
and Lubricants".
LDIA0176E
LDIA0176E
Revision: March 2010 2008 QX56

DLN-242
< ON-VEHICLE MAINTENANCE >[REAR FINAL DRIVE: R230]
DIFFERENTIAL GEAR OIL
ON-VEHICLE MAINTENANCE
DIFFERENTIAL GEAR OIL
Changing Differential Gear OilINFOID:0000000001604457
DRAINING
1. Stop the engine.
2. Remove the drain plug and gasket from the rear final drive
assembly to drain the differential gear oil.
3. Install the drain plug with a new gasket to the rear final drive assembly. Tighten to the specified torque. Refer to DLN-251,
"Disassembly and Assembly".
CAUTION:
Do not reuse gasket.
FILLING
1. Remove the filler plug and gasket from the rear final drive assembly.
2. Fill the rear final drive assembly with new differential gear oil until the level reaches the specified level near the filler plug hole.
3. Install the filler plug with a new gasket on it to the rear final drive assembly. Tighten to the specified torque. Refer to DLN-251,
"Disassembly and Assembly".
CAUTION:
Do not reuse gasket.
Checking Differential Gear OilINFOID:0000000001604458
OIL LEAKAGE AND OIL LEVEL
1. Make sure that differential gear oil is not leaki ng from the rear final drive assembly or around it.
2. Check the differential gear oil level from the filler plug hole as shown.
CAUTION:
Do not start engine while checki ng differential gear oil level.
3. Install the filler plug with a new gasket on it to the rear final drive assembly. Tighten to the specified torque. Refer to DLN-251,
"Disassembly and Assembly".
CAUTION:
Do not reuse gasket.
LLIA0068E
Differential gear oil
grade and capacity : Refer to MA-12, "Fluids and
Lubricants".
LLIA0068E
LLIA0068E
Revision: March 2010
2008 QX56

EC-1
ENGINE
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CONTENTS
ENGINE CONTROL SYSTEM
VK56DE
BASIC INSPECTION ....... .............................
8
DIAGNOSIS AND REPAIR WORKFLOW ..... .....8
Trouble Diagnosis Introduction ........................... ......8
INSPECTION AND ADJUSTMENT ....................13
Basic Inspection .................................................. ....13
Idle Speed and Ignition Timing Check ....................17
Procedure After Replacing ECM .............................17
VIN Registration ......................................................17
Accelerator Pedal Released Position Learning .......18
Throttle Valve Closed Position Learning .................18
Idle Air Volume Learning .........................................18
FUNCTION DIAGNOSIS ..............................21
ENGINE CONTROL SYSTEM ........................ ....21
System Diagram .................................................. ....21
Engine Control Component Parts Location .............22
MULTIPORT FUEL INJECTION SYSTEM ..... ....28
System Description ............................................. ....28
ELECTRIC IGNITION SYSTEM ..................... ....31
System Description ............................................. ....31
AIR CONDITIONING CUT CONTROL ...............32
Input/Output Signal Chart .................................... ....32
System Description .................................................32
AUTOMATIC SPEED CONTROL DEVICE
(ASCD) ...............................................................
33
System Description ............................................. ....33
Component Description ...........................................34
CAN COMMUNICATION ....................................35
System Description ............................................. ....35
COOLING FAN CONTROL ................................36
Description ..............................................................36
EVAPORATIVE EMISSION SYSTEM ...............37
Description ........................................................... ....37
INTAKE VALVE TIMING CONTROL ................40
Description ...............................................................40
ON BOARD DIAGNOSTIC (OBD) SYSTEM ....41
Introduction ..............................................................41
Two Trip Detection Logic .........................................41
Emission-related Diagnostic Information .................42
Malfunction Indicator Lamp (MIL) ............................55
OBD System Operation Chart .................................58
CONSULT-III Function (ENGINE) ...........................63
Generic Scan Tool (GST) Function .........................72
COMPONENT DIAGNOSIS .........................75
TROUBLE DIAGNOSIS - SPECIFICATION
VALUE ...............................................................
75
Description ........................................................... ....75
Testing Condition .....................................................75
Inspection Procedure ...............................................75
Diagnosis Procedure ...............................................76
POWER SUPPLY AND GROUND CIRCUIT ....83
Diagnosis Procedure ...............................................83
Ground Inspection ...................................................86
U1000, U1001 CAN COMM CIRCUIT ...............87
Description ...............................................................87
On Board Diagnosis Logic .......................................87
DTC Confirmation Procedure ..................................87
Diagnosis Procedure ...............................................87
U1010 CONTROL UNIT (CAN) .........................88
Description ...............................................................88
On Board Diagnosis Logic .......................................88
DTC Confirmation Procedure ..................................88
Diagnosis Procedure ...............................................88
P0011, P0021 IVT CONTROL ...........................90
On Board Diagnosis Logic .......................................90
Revision: March 2010 2008 QX56

EC-5
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P1148, P1168 CLOSED LOOP CONTROL ... ..303
On Board Diagnosis Logic .................................. ..303
P1211 TCS CONTROL UNIT ...........................304
Description .......................................................... ..304
On Board Diagnosis Logic ....................................304
DTC Confirmation Procedure ................................304
Diagnosis Procedure .............................................304
P1212 TCS COMMUNICATION LINE ..............305
Description .......................................................... ..305
On Board Diagnosis Logic ....................................305
DTC Confirmation Procedure ................................305
Diagnosis Procedure .............................................305
P1217 ENGINE OVER TEMPERATURE .........306
On Board Diagnosis Logic .................................. ..306
Overall Function Check .........................................306
Diagnosis Procedure .............................................307
Main 13 Causes of Overheating ............................308
P1225 TP SENSOR ..........................................310
Component Description ....................................... ..310
On Board Diagnosis Logic ....................................310
DTC Confirmation Procedure ................................310
Diagnosis Procedure .............................................310
P1226 TP SENSOR ..........................................312
Component Description ....................................... ..312
On Board Diagnosis Logic ....................................312
DTC Confirmation Procedure ................................312
Diagnosis Procedure .............................................312
P1421 COLD START CONTROL .....................314
Description .......................................................... ..314
On Board Diagnosis Logic ....................................314
DTC Confirmation Procedure ................................314
Diagnosis Procedure .............................................314
P1550 BATTERY CURRENT SENSOR ...........316
Component Description ....................................... ..316
On Board Diagnosis Logic ....................................316
DTC Confirmation Procedure ................................316
Diagnosis Procedure .............................................316
Component Inspection ..........................................318
P1551, P1552 BATTERY CURRENT SEN-
SOR ..................................................................
320
Component Description ....................................... ..320
On Board Diagnosis Logic ....................................320
DTC Confirmation Procedure ................................320
Diagnosis Procedure .............................................320
Component Inspection ..........................................322
P1553 BATTERY CURRENT SENSOR ...........324
Component Description ....................................... ..324
On Board Diagnosis Logic ....................................324
DTC Confirmation Procedure ................................324
Diagnosis Procedure .............................................324
Component Inspection ..........................................326
P1554 BATTERY CURRENT SENSOR ..........328
Component Description ....................................... ..328
On Board Diagnosis Logic .....................................328
Overall Function Check .........................................328
Diagnosis Procedure .............................................329
Component Inspection ...........................................330
P1564 ICC STEERING SWITCH .....................332
Component Description .........................................332
On Board Diagnosis Logic .....................................332
DTC Confirmation Procedure ................................332
Diagnosis Procedure .............................................332
Component Inspection ...........................................335
P1564 ASCD STEERING SWITCH .................336
Component Description .........................................336
On Board Diagnosis Logic .....................................336
DTC Confirmation Procedure ................................336
Diagnosis Procedure .............................................336
Component Inspection ...........................................338
P1568 ICC FUNCTION ....................................340
On Board Diagnosis Logic .....................................340
DTC Confirmation Procedure ................................340
Diagnosis Procedure .............................................340
P1572 ICC BRAKE SWITCH ..........................341
Component Description .........................................341
On Board Diagnosis Logic .....................................341
DTC Confirmation Procedure ................................341
Diagnosis Procedure .............................................342
Component Inspection ...........................................346
P1572 ASCD BRAKE SWITCH ......................347
Component Description .........................................347
On Board Diagnosis Logic .....................................347
DTC Confirmation Procedure ................................347
Diagnosis Procedure .............................................348
Component Inspection ...........................................351
P1574 ICC VEHICLE SPEED SENSOR .........352
Component Description .........................................352
On Board Diagnosis Logic .....................................352
DTC Confirmation Procedure ................................352
Diagnosis Procedure .............................................352
P1574 ASCD VEHICLE SPEED SENSOR .....354
Component Description .........................................354
On Board Diagnosis Logic .....................................354
DTC Confirmation Procedure ................................354
Diagnosis Procedure .............................................354
P1805 BRAKE SWITCH .................................356
Description .............................................................356
On Board Diagnosis Logic .....................................356
DTC Confirmation Procedure ................................356
Diagnosis Procedure .............................................356
Component Inspection ...........................................358
P2100, P2103 THROTTLE CONTROL MO-
TOR RELAY ....................................................
359
Revision: March 2010 2008 QX56